Application of reactive multilayers for brazing of solar cells

For joining materials, conventional thermal joining techniques, e.g. welding, brazing and soldering, bring a high amount of thermal energy into the assembly. Due to this, the application of thermal joining techniques is restricted. If high temperatures are neccessary for the generation of the joint, but the parts can only be exposed to them for a short amount of time, the use of reactive nanometer multilayers (RMS) is of great interest. RMS consist of layers with a periodic thickness between 10 and 150 nm. These layers alternate between two materials, e.g. aluminium and nickel. With an ignition impulse an exothermal reaction is started, whose energy can be used to melt solder placed on the surface of the RMS. During the reaction the temperature can raise up to 1900 K, but only for a short period of time and in a limited area.